This invention relates to a method of reducing storage losses in harvested sugar beets and more particularly to treating harvested sugar beets with propylene to reduce storage losses of recoverable sucrose through invert sugar formation and cellular respiration.
In the commercial production of beet sugar, beets are commonly harvested, transported to a beet sugar production facility and then stored, such as in storage piles, at or near the production facility until such time as the harvested beets can be processed to obtain crystalline beet sugar. Sugar beets are commonly stored in piles which may be enclosed, but more typically are outside and exposed to existing weather and temperature variations. In some situations, beets are stored for as long as four to five months prior to processing.
It has been known that a portion of sucrose in stored sugar beets is lost during storage, primarily due to invert sugar formation and cellular respiration. To form invert sugars, sucrose is naturally degraded in the presence of invertase or sucrose synthetase to form the invert hexoses glucose and fructose. The beet cells then utilize the hexose sugars formed by inversion of sucrose, to provide energy required for cellular growth and maintenance, by oxidizing the hexose sugars to carbon dioxide and water. The net result of these natural processes is a loss of sucrose recoverable from the harvested sugar beets during subsequent processing of the beets. The major portion of storage sucrose loss is realized during the early portion of a typical storage period due to higher initial respiration rates caused by higher temperatures immediately succeeding harvest and wounding of the beet tissue during harvesting and piling of the beets.
In the past, attempts have been made to reduce sucrose losses during storage to improve both beet sugar purity and effective sucrose yields. Such attempts have included the utilization of storage trench and canopy systems, storage pile ventilating systems and means to reduce impact damage to beet tissue during piling. Although the foregoing approaches have been utilized to obtain some reduction in sucrose storage losses, they generally require relatively large capital expenditures and result in only a partial reduction in storage losses.
It has now been found that sucrose loss during storage of harvested sugar beets can be significantly reduced by contacting the harvested sugar beets with an effective amount of propylene. The beets can be contacted with propylene by dipping the beets in an aqueous solution of propylene, by spraying an aqueous solution of propylene onto the beets, by contacting the beets with gaseous propylene, or by other suitable means.